A huge wildfire has burned into California’s Yosemite National Park, park officials say.
The week-old Rim Fire grew to 164 sq miles by Friday morning, and had burned 17 sq miles at the edge of the park by the afternoon.
The blaze has forced scores of tourists to flee during peak season and is threatening thousands of homes.
More than 2,000 firefighters have been tackling the flames in difficult terrain. It is just 2% contained.
California Governor Jerry Brown has declared a state of emergency.
The blaze has reached Yosemite’s backcountry at Lake Eleanor, which is accessible by hiking trails, park spokeswoman Kari Cobb told the Associated Press.
“It’s not a very visited part of the park, even though it is very beautiful,” she said, adding the fire was some 20 miles away from Yosemite’s main tourist area.
Kari Cobb said the park service was “not anywhere near” to closing the attraction.
The blaze has shut a stretch of motorway that is one of three entrances to the west side of the park, which receives up to 15,000 visitors a day in the summer.
The Rim Fire is one of 50 major wildfires burning in the western US.
The blaze is centred on Stanislaus National Forest, west of Yosemite, and has so far destroyed two homes and seven outbuildings.
A spokeswoman for the US Forest Service said 4,500 homes, hotels, businesses and several campsites are under threat as of Friday, up from 2,500 the day before.
Officials have gone door to door in the summer community of Pine Mountain Lake urging people to leave.
Local residents said the area, normally teeming with tourists, is now empty.
“This fire, it’s killing our financial picture,” restaurant owner Corinna Loh told the Associated Press.
“This is our high season and it has gone to nothing. We’re really hurting.”
Lee Bentley of the US Forest Service told CBS News: “We’ve got a monster on our hands. This fire is making its own weather.
“It’s going every which direction. This is one of the worst I’ve ever been on. I’ve been doing it for quite a few years.”
The area’s steep hills and rugged terrain are hampering firefighters’ efforts, officials say.
Despite the blaze’s proximity to Yosemite, spokesman Scott Gediman says the park is clear of smoke, and all accommodation and attractions are open.
Meanwhile, five wildfires in Yellowstone National Park have scorched about 18 square miles of mostly remote areas.